Hypothetically, for the continuity of the story, I'm guessing they went with the story arc of it not happening. But I'd wager the content will alter the end of the game and remove the option of actually utilizing the purifier. Because if it had been used, not just ghouls and mutants would die but almost every wastelander including the player, provided they did Moira's quest. That or they're just drinking bottled water from uninfected sources.... Take what you will from it.